1. Field of the Invention
The claimed subject matter concerns management of acknowledgements and more particularly, management of acknowledgements through the selective use of control channel element (CCE)-based implicit pointing.
2. Description of the Related Art
There is a general move in the wireless industry towards broadband communications. In particular, LTE, which is a Third Generation Partnership Project (3GPP) standard, is the next step forward in cellular third generation (3G) services. As is known in the art, through the use of LTE, a base station can support multiple user elements (UE), or mobile stations, particularly through a technique referred to as multiple user multiple-input multiple-output (MU MIMO). In this arrangement, it may be necessary for the base station to provide acknowledgements that include positive acknowledgements (ACK) or negative acknowledgements (NACK) over a downlink (DL) channel to the UEs to allow the UEs to determine whether their transmissions to the base station were properly received.
It is desirable, however, to limit the overhead required for signaling the UEs with the DL ACKs or NACKs. One way to help minimize the use of valuable resources is to generate an ACK/NACK channel bank (ACK/NACK bank). An ACK/NACK channel bank is a set of frequency resources (resource elements also called sub-carriers or frequency bins or tones) for conveying ACK/NACK information to each scheduled UE, which are contained in the control region of a subframe in the DL channel of LTE. The UEs must refer to the ACK/NACK bank to determine whether their transmissions to the base station were properly received. Significantly, however, because of the ambiguity involved in the multiplexing of UEs on an allocated MU-MIMO resource in a subframe, it is necessary to construct and transmit on multiple ACK/NACK banks, which is a waste of valuable bandwidth.